2 Types of Compounds There are two types of compounds. Ionic: Covalent: a metal and an nonmetalCovalent:contain two nonmetals
3 Ionic CompoundsMust contain a positive ion (cation) and negative ion (anion).The cation (metal) is written first, the anion (nonmetal) is written second.The total charge on the compound must equal 0.
4 Naming Binary Ionic Compounds #1 – Name the metal (written on periodic table)#2 – Name the nonmetal, changing the ending to –ide.Examples:MgOCaCl2NaBrSr3P2magnesium oxidecalcium chloridesodium bromidestrontium phosphide
5 Writing FormulasThe subscripts tell how many of each atom you have. (The overall charge must equal zero!!)EXAMPLE: Write the chemical formula for the compound containing Al and Br.#1 – determine the chargesAl Br-1
6 Al+3 Br-1 AlBr3 #2 – cross the charges. #3 – Write the formula, simplify if neededAlBr313
7 Try this one…Write the chemical formula for the compound containing Mg and S#1 – determine the chargesMg S-2
8 Mg+2 S-2 Mg2S2 MgS #2 – cross the charges. #3 – Write the formula, simplify if neededMg2S2MgS22
9 Ionic Compounds with Polyatomic Ions #1 – name the 1st part of the compound#2 – name the 2nd partIf it is a polyatomic ion, DO NOT change the endingIf it is a nonmetal, change to –ide.Examples:CaCO3Na3SO4(NH4)2SCalcium carbonateSodium sulfateAmmonium sulfide
10 Writing Formulas: Na+1 OH-1 NaOH Same rules apply, except if the polyatomic ion gets a subscript you MUST use parentheses around it.Example:Write the formula for sodium hydroxide.Na OH-1NaOH11
11 Writing Formulas for Polyatomic Compounds Calcium phosphateCa PO4-3Ca3(PO4)232
13 HomeworkPage 221Problems 19, 20, 21 and 22Page 233Problem 83
14 Compounds Containing Metals with Variable Charges
15 Variable Charges (Transition Metals) Metals in Group 1, Group 2, Zinc (+2), Silver (+1) and Aluminum only have one charge.The rest have variable charges so we have to tell what charge the ion has in our compound when we name it.
16 Naming #1 – Name the metal. #2 – Add a roman numeral telling the charge on the metal in parentheses.I-1 II-2 III-3 IV-4 V-5 VI-6 VII-7#3 – Name the negative ion as before.
17 Example CrO O is a -2 charge To make a neutral compound, Cr must be a +2.Chromium (II) oxide
18 FeCl3 Cl is a -1 charge There are 3 chlorine ions -3 The ONE Fe must be a +3Iron (III) chloride
19 CoCO3Carbonate is a -2Co is a +2Cobalt (II) carbonate
20 Ni3(PO4)2 Phosphate = -3 x 2 = -6 There are 3 nickel atoms so each one = +2 to equal +6Nickel (II) phosphate
21 Mn(SO4)2 Sulfate is -2, there are two -4 so the ONE Manganese = +4 Manganese (IV) sulfate